Cleanup block made test crash when using multiple assignment

The following test reports a compilation error: 

    def testMultipleAssignment() {
        setup:
        File file = new File('x')

        when:
        def (x,y,z) = [1,2,3]

        then:
        x == 1
        y == 2
        z == 3

        cleanup:
        file?.delete()
    }

Spock version: 0.7-groovy-2.0; Groovy version: 2.1.2

Here it is the error stack trace: 

Groovyc: Unexpected error during compilation of spec 'ListTest'. Maybe you have 
used invalid Spock syntax? Anyway, please file a bug report at 
http://issues.spockframework.org.
java.lang.ClassCastException: 
org.codehaus.groovy.ast.expr.ArgumentListExpression cannot be cast to 
org.codehaus.groovy.ast.expr.VariableExpression
    at org.codehaus.groovy.ast.expr.DeclarationExpression.getVariableExpression(DeclarationExpression.java:103)
    at org.spockframework.compiler.SpecRewriter.moveVariableDeclarations(SpecRewriter.java:538)
    at org.spockframework.compiler.SpecRewriter.visitCleanupBlock(SpecRewriter.java:371)
    at org.spockframework.compiler.model.CleanupBlock.accept(CleanupBlock.java:33)
    at org.spockframework.compiler.model.Method.accept(Method.java:70)
    at org.spockframework.compiler.model.Spec.accept(Spec.java:113)
    at org.spockframework.compiler.SpockTransform$Impl.processSpec(SpockTransform.java:77)
    at org.spockframework.compiler.SpockTransform$Impl.visit(SpockTransform.java:64)
    at org.spockframework.compiler.SpockTransform.visit(SpockTransform.java:47)
    at org.codehaus.groovy.transform.ASTTransformationVisitor$3.call(ASTTransformationVisitor.java:319)
    at org.codehaus.groovy.control.CompilationUnit.applyToSourceUnits(CompilationUnit.java:912)
    at org.codehaus.groovy.control.CompilationUnit.doPhaseOperation(CompilationUnit.java:575)
    at org.codehaus.groovy.control.CompilationUnit.processPhaseOperations(CompilationUnit.java:551)
    at org.codehaus.groovy.control.CompilationUnit.compile(CompilationUnit.java:528)
    at org.jetbrains.groovy.compiler.rt.GroovyCompilerWrapper.compile(GroovyCompilerWrapper.java:46)
    at org.jetbrains.groovy.compiler.rt.GroovycRunner.main(GroovycRunner.java:132)
    at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
    at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:39)
    at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:25)
    at java.lang.reflect.Method.invoke(Method.java:597)
    at com.intellij.rt.execution.CommandLineWrapper.main(CommandLineWrapper.java:112)
Original issue reported on code.google.com by paolo.ditommaso on 23 Mar 2013 at 9:33
Merged into: #297
thenirajpandey / spock

Cleanup block made test crash when using multiple assignment #304
